Drill bit



Jul 22 1924. 1,502,463

G. W. DUNSWORTH DRILL BIT Filed Dec. 26; 1922 I5 Sheets-Sheet 1 gwucnfozG. W. DUNSWORTH DRILL BIT Filed Dec. 26, i922 3 Sheets5heet 2 @W KQR G.W. DUNSWORTH DRILL BIT Filed Dec. 26, 1922 3 Sheets-Sheet 5 PatentedJuly 22, 1924.

UNITED STATES GEORGE W. DUNSWORTH, OF HOUSTON, TEXAS.

DRILL .BI'I'.

Application filed December 26, 1922. Serial No. 609,150.

To all whom it may concern:

Be it known that I, GEORGE W. DUNS- WORTH, citizen of the United.States, residing at Houston, in the county of Harris and State of Texas,have invented certain new and useful Improvements in Drill Bits, ofwhich the following is a specification.

This invention relates to new and useful improvements in a drill bit.

One object of the invention is to provide a bit of the characterdescribed specially designed for the purposeof drilling and reamingbores, and also for underreaming bores underneath the casing to permitthe casing to descend as drilling progresses.

A further feature of the invention resides in the provision of a bit ofthe character described which may be readily attached to the lower endof a drill stem, or detached therefrom and withdrawn through the stem,without withdrawing the stem from the bore, a diflicult and laborioustask.

Another object of the invention is to provide a drill bit of thecharacter described whose cutting points may be readily detaohedfor'repairs or replacements.

With'the above and other objects in view the invention has particularrelation to certain novel features of construction, operation andarrangement of parts, an example of which is given in this specificationand illustrated in the accompanying drawings, wherein Figure 1 is avertical sectional view of the bit.

Figure 2 is a side View shown partially in section.

Figure 3 is a transverse sectional view taken on the line 3-3 of Figure1.

Figure 4 is a transverse sectional view taken on the line 4-4 of Figure1.

Figure 5 shows a side view of a grappling tool employed for letting thebit down into and withdrawing it from the stem.

Figure 6 shows a side view thereof taken at right angles to the viewshown in Figure 5 and shown partially in section. Figure 7 shows a sideview of the lower section of the drill stem shown partly in section. I

Figure 8 shows a sideview of a type of collar employed. 7'

Figure 9 shows a side V18W-, of the bit shank and,

Figure 10 shows a side view thereof taken at right angles to the viewshown in Figure 9 and shown partly in section.

In the drawings the numeral 1 designates the lower section of the drillstem whose upper end is reduced at 2 and outwardly threaded to receivethe lower end of the section above it. The complete stem extends tothetop of the ground and is rotated by the conventional well knownrotary. The lower section 1 has theoppositely disposed inclined ribs 3,3 secured to the inner wall thereof. The upper ends of these ribs arebeveled or tapered as at 4' and their lower ends are turned forwardlyforming the ledges 5, 5 and the depending lugs 6, 6 which depend fromthe lower end of said section and the forward sides of these lugs formthe abrupt shoulders 7 7 The numeral 8 designates a tubular bodypreferably formed of two sections screwedtogether and formed withoppositely disposed inclined slots 8. Flushing water is forced downbetween the stem 1 and the body 8, then thru the space between the bodyand the collar23, thru the slots 8 inside the body 8. The lower end ofthis tubular body is threaded onto a head 9 which has the vertical watercourses 10, 10 therethrough to permit the passage of water downwardly tothe cutting points of the bit, and also has the vertical central bearing11 to receive the twisted stem 12 of the bit shank 13. This shank has athreaded socket 14 to receive the reduced threaded extension of the bit15. The shank 13 also has the oppositely dis osed lugs 16 on its upperend which inter ock in the transverse groove 17 of the head 9.

' This head has oppositely disposed sockets 18, 18. to receive thespherical shaped balls or joint members 19, 19 of the reamin blades 20,20. An annular head 21 is fitted around the band 9 and prevents thedetachment of the blades 20, and this band is held in place by means ofan open flexible ring 22 which surrounds the head and is interposedbetween said band and the lower end of the body 8. When it is desired toremove said blades for repairs or replace; ments the ring 22 may beopened and slipped from the head and the band 21 then moved upwardly onsaid head and the blades then readily detached. When the bit is inexpanded or working position the lugs 7 fit closely against the rearside of the blades 20 and relnforce them. Loosely surrounding thetubular body 8 there is a slidable collar 23 having the dependingfingers 24, 24. slightly spiralled. A yoke 25 is carried by the upperend of the stem 12 and has the oppositely disposed pins 26, 26 whichwork through the slots 8 and whose ends have bearings in the collar 23.

In Figures 5 and 6 there is shown a grappling tool for letting the bitdown through the drill stem and attaching it, and for withdrawing saidbit. The numeral 27 designates a plug which is screwed into the upperend of the body 8 and has the upstanding stem 28 formed with a conicalshaped head 29. This head is formed for engagement with the hooks 30, 30of said grappling tool 31, and said tool has a bail 32 for theattachment of a cable through which it is handled. The grappling tool initself forms no part of this invention and will not be furtherdescribed.

As the drill is being let down through the stem 1, the bit shank 13 andthe bit 15 will hang suspended from the yoke 25 whose pins 26 will restat the lower end of the slots 8', and the collar 23 will be in its lowerposition. As the bit '15 approaches the bottom of the bore the fingers24, 24 will pass between the ribs 3, 3, in the position illustrated inFigure 2 and the upper ends of said ribs will engage under the slidablecollar 23 and hold the same against downward movement while the body 8moves on downwardly a distance equal to the length of the slots 8, andthe reaming blades will be forced outwardly by the outwardly inclinedgroove-like guides 33 cut in opposite sides of the shank 13 in whichsaid blades work.

The lower end of the head 9 has oppositely.

disposed lugs 34, 34 which seat on the ledges 5 and interlock said headwith the drill stem, and at the same time the lugs 16 seat in thetransverse groove 17 to interlock the bit shank 13 with the head 9 andthe rota tion of the stem will thus be imparted to the head 9 and thebit 15. 4

i As above stated the stem 12 of the bit shank is twisted or augurshaped and as rotation is imparted to the stem in a clockwise or righthand direction this twisted stem will have a tendency to hold the shank13 up closely against the head 9 to prevent the unseating of the lugs 16from the groove 17. The ribs 3 and fingers 24 are correspondinglyinclined or spiralled forming the abutting faces 35 and 36 whichinterlock together while the stem is rotating with a wedge-like effect,thus having an additional tendency to lock the parts together and toprevent the bit from collapsing, due to the vibration or jumping of thestem when piercing hard strata.

When it is desired to detach the bit an upward pull is exerted on theggaippling tool and this will lift the tubular y 8, carrying the head 9,upwardly and withdrawing the reaming blades 20 within the same, and whenthe lower ends of the slots 8 engage with the pins 26 and the yoke 25the bit shank and bit will be carried upwardly and the entire bit may beunit through the stem.

What I claim is:

1. A device of the character described including a tubular stem, a bitadapted to be passed through said stem and attached to, or detachedfrom, the lower end thereof, said bit including a central boring tool,and lateral reamers, said stem and bit having cooperating, spiralledabutting parts, which interlock when the stem is :otated.

2. A device of the character described including a tubular stem, a bitadapted to be passed through said stem and attached to, or detachedfrom, the lower end thereof, said bit including a central boring tool,and lateral reaming cutters, said reaming cutters projecting outlaterally beyond the stem -when in operative position, means carried bysaid stem and bit respectively, for projecting said reaming cutters intooperative position, and spira led interlocking means which secure saidbit in working position while the stem is rotated.

3. A device of the character described including a tubular stem, a bitadapted to be passed through said stem and attached to, or detachedfrom, the lower end thereof, said bit including a central boring blade,and lateral reaming blades, said reaming blades projecting out laterallybeyond the stem when in operative position, and coacting means, carriedby said stem and bit, respectively, for projecting said reaming bladesinto, and locking them in, operative position.

4. The combination with a tubular stem of a bit adapted to be passedthrough the stem'and attached to, or detached from, the lower endthereof, said bit including a tubular body, a head carried by the lowerend thereof, reaming blades pivoted in said head, a shank having atwisted stem which works through a correspondingly shaped bearing insaid head and which is connected to, but has a limited vertical movementrelative to said body, said shank having downwardly diverging bearingfaces adapted to spread said reamin blades as said head moves towardsaid s ank} 1 5. A device of the character described including a tubularstem, a boring tool adapted to pass through said stem and including abody, a head connected to the lower end of the body, a reaming bladepivoted to the head, a slidable member on said body and having a limitedvertical movement thereon, a bit shank connected to said member andformed with a diverging bearing,'means within the lower end of the stempulled on out as a which engage with said member and arrest the downwardmovement of the same and the shank connected thereto, permitting saidhead and blade to move on downwardly relative to the shank wherebysaid-blade is L projected outwardly by said bearing.

6. A device of the character described including a tubular stem, aboring tool adapted to pass through said stem and including a body, ahead connected to the lower end of the body, a reaming blade pivoted tothe head, a slidable member on said body and having a limited verticalmovement thereon, a bit shank connected to said member and formed with adivergin bearing, means within the lower end of t e stem which engagewith s aid member and arrest the downward movement of the same and theshank connected thereto, permitting said head and blade to move ondownwardly relative to the shank whereby said blade is projectedoutwardly by said bearing, spiralled interlocking means operating tosecure said blades in projected position during the rotation ofthe stem,and a bit attached to said shank.

7. A device of the character described including a tubular stem, aboring tool adapted to pass through said stem and including a body, ahead connected to the lower end of the body, a reaming blade pivoted tothe head, a slidable member on said body and having a limited verticalmovement thereon, a bit shank connected to said mem-' her and formedwith a diverging bearing, means within the lower end of the stem whichengage with said member and arrest the downward movement of the same andthe shank connected thereto, permitting said head and blade to move ondownwardly relative to the shank whereby said blade is projectedoutwardly by said bearing, and means for interlocking the stem with saidboring tool when the bit is in operative position to transmit rotationfrom the former to the latter.

8. A device of the character described in-v cluding a tubular stem, aboring tool adapted to be passed through said stem and including a bodyhaving oppositely disposed slots, a head connected to the lower end ofsaid body and having a central bearing,

' reaming blades pivoted to the head, a slidable collar on said body, ayoke whose respective ends work through said slots and having bearingsin said collar, a bit shank formed with a stem which works through saidcentral bearing and is attached tosaid yoke said shank having divergingbearings, means within the lower end of the stem which engage againstsaid collar and arrest the downward movement thereof, and the shankconnected thereto, permitting said head and blades to move on downwardlyrelative to the shank whereby said blades having bearings in saidcollar, a bit shank formed with a stem which works through said centralbearing and is attached to said yoke, said shank having divergingbearings,

means within the lower end of the stem which engage against said collarand arrest the downward movement thereof, and the shank connectedthereto, permitting said head and blades to move on downwardly relativeto the shank whereby said blades are projected downwardly beyond saidstem by said bearings, and interlocking means through which said bladesand shank are connected with the stem and rotation imparted to theboring tool through said stem.

10. A device of the character described including a tubular stem, aboring tool adapted to be passed through said stem and including a bodyhaving oppositely disposed slots, a head connected to the lower end ofsaid body and having a central bearing, reaming blades pivoted to thehead, a

slidable collar on said body, a yoke whose respective ends work throughsaid slots and having bearings in said collar, a bit shank formed with astem which works through said central'bearing and is attached to saidyoke, said shank having divergin bearings, means within the lower end 0the stem which engage against said collar and arrest the downwardmovement thereot, and the shank connected thereto, permitting said headand blades to move on downwardly relative to the shank whereby saidblades are projected downwardly beyond said-stem by said bearings,spiralled interlocking means securing the bit in Working position duringthe rotation of the stem, a bit connected to said shank, said bit andblades being detachable.

11. A device of the character described including a tubular stem, aboring tool adapted to be passed through said stem and including a bodyhaving oppositely disposed slots, a head connected to the lower end ofsaid body and having a central bear ing, reaming blades pivoted to thehead, a slidable collar on said, body, a yoke whose respective ends workthrough said slots and having bearings in said collar, a bit shankformed with a stem which works through said central bearing andisattached to said yoke, said shank having diverging bearings, meanswithin the lower end of the stem which engage against saidcollar andarrest the downward movement thereof, and the shank connected thereto,permitting said head and blades to move on downwardly 5 relative to theshank whereby said blades are projected downwardly beyond said stem bysaid bearings, a bit connected to said shank, said bit and blades beingdetachable, interlocking means between the stem and 10 boring toolthrough which the rotation of the former is transmitted to the latter,and

spiralled interlocking means between said stem and bit mechanism holdingsaid bit in working relation with the stem during the rotation of thelatter.

In testimony whereof I have name to this specification in the twosubscribing witnesses.

GEORGE W. DUN SWORTH.

Witnesses: Y

W. H. DUNLAY, E. V. HARDWAY,

signed my presence of

